Moisture + Friction = Enemy!

June 4, 2010
Share with your friends


The root of all evils when it comes to blister formation is moisture. As the humidity rises, moisture content in the air also rises, leading to increased perspiration and friction between feet, socks and shoes! Blister formation occurs when friction and moisture combine separating the top layer of skin (epidermis) from the layer below (dermis) allowing the area to fill with fluid. Often times, the fluid is clear, but can be bloody or infection filled. For simplicity, we will address the most common form of blistering on the feet; those filled with clear fluid.

No one is immune to blistering and time again, athletes pull over at the medical tent during their marathon or charity-walking event, for blister care. In the summer month, sandals tend to induce blisters between toes, or on the sole of the feet, as motion of the foot isn’t well controlled in a sandal and that extra motion combined with moisture, creates friction and blister formation. Depending on the location of the blister, some are much more painful than others and can inhibit daily activities. The following “Blister Tips” address some of the myths in treating blisters and will guide you towards appropriate treatment.

1. Don’t pop blisters at home! It can be rather tempting to pop a fresh blister and relieve the pressure by expressing the fluid, but that’s not recommended. Blisters, by nature, contain sterile fluid, meaning that there is no bacterium inside and infection is a remote possibility. If you decide to pop a blister with a needle that you might have “sterilized” in your bathroom, you run the risk of inducing infection. Not only from the needle, but also because now you’ve exposed this sterile environment to the outside environment. Resist the urge to pop your blister and allow your body to resorb blister fluid on its own.
2. If I shouldn’t pop blisters at home, why does the medical staff pop them during a race? In an acute setting, such as during a marathon, blisters are typically popped by the medical staff. The reason: immediate relief of the excess pressure allows runners to continue through the remainder of the competition. The medical staff cleans the skin surrounding the blister with alcohol, uses a sterile needle to puncture the skin, and drains fluid out at it’s lowest point of gravity. Although the method isn’t perfect, and not recommended at home, the medical staff does their best to prevent infection while providing immediately relief for the athlete.
3. What to do if your blister pops on its own: As mentioned above, once your blister is exposed to the outside environment, infection becomes a possibility as there is now an entry point for bacterium. When this occurs, you need to do your best to keep the blistered area extremely clean. Using warm water and soap is sufficient, making sure to dry the area thoroughly and protect it using a band-aid that covers the entire blister. Avoid using hydrogen peroxide to cleanse the area. If dead skin remains, leave the skin in place, as it is still capable of providing a barrier for infection while providing a good environment for new skin to grow underneath.
4. Get your feet measured for shoe-size accuracy. As we’ve mentioned, blisters are mainly caused by friction combined with moisture. Shoes that are tight in the wrong places can cause recurrent irritation and frequent blistering. Getting your feet measured for an accurate shoe size can make a difference if you’ve been wearing the wrong size! Adjusting your running shoes to fit your feet may also increase your distance and comfort level while engaging in activity.
5. Blisters can occur separate from friction and moisture. Blisters that are small in size and seem to continually appear for unexplained reasons may indicate a problem separate from friction and moisture. Check the other areas of your feet looking for scaly skin on the soles and heels. If you find areas of scaly skin, it is likely that you have a fungal infection and the blister formation is a result of that. Contact your Podiatrist for an appointment, as they can treat your fungal infection quickly with topical medications!
6. Prevention is your best option! The goal in prevention is to decrease friction and eliminate moisture, as those are the most common predisposing factors. As discussed wearing shoes that fit your foot size is important in decreasing areas of pressure where friction is imminent. In addition, keeping your feet dry and wearing socks that allow the feet to breath, versus cotton socks that hold in moisture, is very important. Finally, treating any underlying conditions such as fungus that may be causing blister formation will help tremendously in prevention.

  • Recent Posts

  • Categories